Orion 07762 Deluxe Safety Film Solar Filter 12.13 Inch Inside Diameter (Silver) Explore the Sun safely through a telescope with this high-quality solar filter featuring Baader film in a sturdy aluminum cell Fits 11 inch SCT, Celestron CGE Pro 1100 HD, XLT Edge HD 1100, CGEM 1100 HD, and CPC 1100 telescopes Each filter is mounted in a foam-lined, clear-anodized aluminum cell featuring three equidistant securing thumbscrews for secure telescope attachment This filter features an inside diameter of 12.31 inches - it is designed to fit optical tubes with an outer diameter of 12.06 inches to 12.31 inches with included shim materials and securing thumbscrews Note: All Orion solar filters are designed for use with an adequate friction fit attachment. Thumbscrews should only be used to keep filter securely in place once a friction fit has been achieved